Method of manufacturing seamless tubes.



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Pantemed Nov. 1, 1910.

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o BBIBDB METHOD OF MANUPAGTURING SEAMLBSS TUBES. y

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O/ l f OTTO BBIEDE, OF .'BEJRATH, NEAR DUSSELDORF, GERMANY.

.- METHOD orilzanarac'rvmne snAmLnss TUBES.

To all 'whom 'it may concern:

Be it known that I, O'i'ro Barnim, residing at Benrath, near Dusseldorf,Province of the Rhine, German Empire, a subject of the German Emperor,liaveinvented or discovered certain new and useful Improvements inMethods of lllanufjacturing Seamless- Tubes, of which improvement thefollowing is a specification.

1o Heretofore in reducing hollow billets to tubes, the billet was madeof an internal diameter corresponding approximately to that desired inthe finished tube, but the external diameter is made greater than thatof the finished tube. And reduction is effected by subjecti the externalsurface of the billet to reducing surfaces of y progressively reducedcaliber. In other werds, during reduction from billet to tube, theinternal di- Y ameter of the former remains practically 'unchanged whilethe external diameter is reduced.

The invention described herein has for its object the reduction of ahollow billet to tube form by increasing the internal diameter ofthebillet, without decreasing the external diameter of the finished tube materially beyond the original external diameter of the billet. Theinvention is hereinafter rr ire fully y. described and claimed.

` In the accompanying drawings forming a part of this specilicationFigures 1 and 2 show in side elevation different forms of mandrels, Fig.3 is' a diagrammatic View illustrati o' m im roved method. Fi 4 nh y p gprovided with a suitable coupling member l shows transverse sections inplanes indicated respectively by w-a, b-b, {:--c, and Fig. 3; Fig. 5 isa view showing the vposition 40 of the billet and mandrelv at thebeginning of a forward or working strokeand after the rolls have beenseparated ai/id the inandrel and billet turned axially ninety degrees;Fig.- 6 is a transverse section in a lane indicated by the line c-e Fig.5; Fig.

is a. view partly in section and partly 1n elevation of a forni ofapparat.us adapted to the prartice of my invention;-

1g. 8 is a transverse section in a lane indicated by the line VIII-NIH;Fig. 8 is a sectional detail view illustrating a portion of the feedmechanism. Fig. 9 is a diagrammatic view illustrating the employment ofu. plu# rality of pairs of rolls and Fig. 10 is asec- 55 tional view ofanother form of mill adapted Specication of Letters Patent.

Application led February 15, 1910.' Serial No. 544,082.

-Patented Nov. 1, 1910.

tn the practice of the invention and Fig. 11 is a sectional plan of thesaine.

In' the practice 'of my invention, the billet is rolled or otherwisereduced to a diameter equal or approximately equal to the external 151)Ai diameter desired in the tubeto be formed. After the billet has beenpierced, which how ever-is not necessary, it is slipped onto' a mandrel1 having a portionof theA end enlarged and conical as at 2 and anadjacent 85 Y portion 3V cylindrical and of .a diameter equal to thedesired internal diameter of the finished tube. The portion 2, which maybe of any suitable form as for example a cone with straight sides 'ass'hown in Fig. 1 or a 70 paraboloid as shown in Fig. 2, connects thestem 4 of the mandrel with the cylindrical portion 3. It ispreferredthat the cylinc drical portion should be given a slight taperfrom or approximately from the plane of junction of the portions 2 and3, so as to facilitate the movement of the finished p01'-l tions of thetube ofi of the cylindrical fi'nisli-L ing portion of the mandrel.

Afterthe billet has been slipped on the mandrel the stem 4 of the latteris connected to a suitable mechanism for reciprocating it and after eachreducing movement, imparting a partial rotation to the mandrel. Asuitable form of such mechanism consists of a slide 5 mounted on a bed 6which is arranged in feed relation to the reduc rolls 7. This slide isconnected to a cran arm 8 of the shaft 9 which'can be rotated by anysuitable means. A connecting shaft 10 is rotatably mounted on the slideand is 11 whereby it may be connected to the stem of the mandrel as-shown in Fig. 7. Any suitable means may be employedjor rotating themandrel and billet as for example one end of a clock spring 12 may beattached to the shaft 10 and its opposite end to an externally toothedshell 13 en aging a pinion 14 loosely mounted on a s aft 15, 100

von which is loosely mounted a pinion 16 having angularly arranged teethadapted to engage inclined teeth on a stationary rack bar 17. The shaft15 is mounted in suitable brackets depending from the slide 5, and itreciprocates with the latter. l'lherefore when the slide is reciprocatedcorresponding back-and forth rotation will be imparted to the pinion 16.When the pinion is rotated in one direction z'. e. during a 110 therebyrotating the toothed shell 13 and v placing the spring under tension,which will become operative to rotate the mandrel and billet as soon asthe latter is released from the grip of the rolls at the end of theworking stroke.' During the return stroke of the slide the toothed shellwill not be rotated. Provision is made for forcing the billet farther inthe mandrel at the end of the `reducing stroke of the latter. A.convenient means to this end consists of a ratchet dish 18 keyed to ascrew threaded spindle 51 mounted for rotation in suitable bearings ofthe frame of the machine. The awl b of the said ratchet disk is disposeon a rocker arm 52 mounted on the spindle 5l. A finger of the saidrocker arm is adapted to be engaged and to be rocked by a cam face 53provided on the slide 5 whenever the latter reaches the end of itsreturn stroke. By the pawlv b such rocking movement is transmitted tothe ratchet disk 18 and the vspindle 51. When released from the said camthe rocker arm is retracted into its normal position by a spring. Theshaft 51 is threaded and engages a threaded opening through a downwardlyprojecting lug21 on a slide 19 which is provided with a wall or abutment20, adapted to bear against the rear end of the. billet. In order thatthe whole of the billet may be reduced, a sleeve 23 is interposedbetween the rear end of the billet and the abutment, said sleeve beingpreferably integral with the abutment 20 and made of a length a littlegreater than that of the conical ortion of the mandrel and of suchinterna shape and dimensions that such conical portion may enter thesleeve. The abutment 20 is advanced toward the mandrel whenever theslide reaches the end cf its return stroke. In order that the billet maybe turned axially after each forward movement, provision is v made forrelieving the exterior surface of the billet of any retarding Jrictional resistance of the rolls. This can be accomplished in manyways, as by using recessed or sectional rolls or swages, well known inthis art, or by separat-ing the rolls a sutlicient distance to permit ofthe free movement of the billet axially and longitudinally.

As shown in Fig.'7 provision is made for shifting one of the rollstoward and fromk the other by means of wedges 24 movable under thejournal boxes of the lower roll. These wedges should be shifted to dropthe lower roll at or about the time the billet and mandrel reach thelimit of their forward or reducing movement. At. or about the time themandrel reaches the limit of its return or non-working movement. thelower roll is again raised to its operative or reducing position. Thesemovements of the wedges to raise the roll are effected hy any suitablemeans, as for example by a cam 25 on the shaft 9 acting von an arm 25lon a counter shaft 26 which is provided with arms 27 connected by rods28 to thewedges, which are shifted in the opposite direction to drop thelower roll by springs 29 or other suitable means.

In describing the method as carried out by the construction shown inFigs. 3 to 8 inclusive, it will be understood that a reduction has beencompleted by the rolls and that the latter and the billet and mandrelare in the position shown in Fig. 3. During such reduction the billethas been caused to assume the transverse relations to the mandrel shownin Fig. 4, by the rolls which are provided with grooves forming an ovalpass, so as to avoid tinning of the metal. As soon as the several partsreach the position shown in Fig. 3 the billet is released from the biteof the rolls by dropping the lower roll, and the rear end of the billetstrikes against the shiftable abutment 23, so that it is slipped fartheron the mandrel. This action is facilitated by the oval shape of thebillet imparted thereto by the previous reducing operation. By thismovement of the mandrel into the billet the latter is enlargedperipherally along that portion in contact with the conical portion ofthe mandrel as indicated in Fig. Furthermore the turning mechanism isthrown into operation, and turns the billet at an angle of 90 degrees,whereupon the mandrel and bil# let perform their return movement to theleft. At the end of their return movement Y the billet and mandrel aremoved forward or in a direction to cause a reduction of the portionofthe billet enlarged by the mandrel, the metal displaced in suchreductions causing an elongationv along the portion operated on. Asbefore stated the grooves in the rolls are so shaped as to form anapproximately oval pass or of such shape and dimensions relative to thetube to be roduced that the upper and lower walls o.. the pass will actreduetively on about'one quarter of the perimeter of the billet; and asthe billet at the beginning of each reduction is circular orapproximately so in cross-section the pressure of the rolls will causenot only a longitudinal ow of the metal but also and to a limited extenta lateral flow so that the side ortions of the billet will be forcedaway from the mandrel. After a reducing movementvof the billet andninndrel or one to the right in Figs. 5 and 7, the billet is relieved ofthe pressure of the rolls, the billet and mandrel are turned through anare of 90 to the position shown in Fig.

6.. and the mandrel and billet moved relative to each other so as toYcause an enlargement of a portion of the billet for a distance ap-A calportionk of the mandrel. f

It will. be observed that two reducin e1ements are employed z'. e.tliemandre and the grooved rolls or sw'aging or reducing members.v It isimmaterial which of these, .the mandrel or rolls, is moved relative toproximatelv equal to the length of the conithe other. Inaddition to thereducing elements, a feeding movement'of the billet relativeto themandrel is effected intermediate of billet Vreducing operations. Therolls f while reducing the billet should have a. peripheralmovementcorresponding to the rec- Y rolls.

tilinear movement of the billet and this movement of the rolls may beeilected in any suitable manner, as for instance by contact with thesurface of the billet. As shown in Fig. 9 a plurality of pairs of rollsmay be I employed, successive pairs of rolls being arranged with theiraxes at an angle to the axes of adjacentl rclls. When using a plu..

rality of pairs of rolls the billet need not be turned axially and if asulicient number of pairs be employed a billet may be reduced to tubeform by acontinuous movement through a single train of rolls.

In Fig. 10 is shown a mill adapted to the practice of the improvedmethod and having the rolls rotatin in a plane at an acute angle to theaxis o the mandrel, whereby the path of the rolls on the billet can beof any desired length by changing the angular relation of the rolls tothe axis of the billet. In this construction the rolls are positivelydriven in such direction as to travel in a spiral path from a pointad'acent to the point of the conical portion o the mandrel j to thecylindrical portion thereof, and `to` this end provision is madepermitting a. movement of the mandrel carrying the billet and the rollsrelative one to the other. In the construction shown, the housing 30 inwhich the rolls 31 are mounted with .their axes at an angle to eachother and to the axes of the mandrel '1, is stationary while the bed 32carrying the mandrel and the billet feeding means is movable relative tothe In the construction 4shown the bed 32 is provided at its ends withvertical abutments 33 and 34 which carry fluid pressure cylinders soarranged that their rams or pistons 35 and 36 bear against o positesides of the housing 30. By means ci) suitable valve mechanism such asis well known in the art the low ofv fluid pressure to and from saidcylinders is regulated to eifect any desired movement of the bed andparts carried thereby relative tothe rolls. A fluid pressure cylinderand piston 37. are so mounted onV the abutment 33 as to be capable offorcing the billet into the mandre which is held as ings 38-and 39 areinterposed between the piston rod and billet, and between the mantionshown wedges 40 are employed for shifting the lower roll. The end 43 ofone of the Wedges strikes against and is shifted by a stop 44 at the endof the working stroke thereby permit-ting the lower roll to drop and atthe end of the return or dead stroke or movement the face 41 will strikethe abutment 42 and shift the wedges in a direction to cause the rollsto assume normal or operative relation to the billet.

In the mill shown in Fig. 10 the rolls will cause a reduction of theportion of the wall of the billet forced by the action of the mandrelsubstantially as before stated. By arranging the rolls as in Fig. 10 theconical,

portion ofthe mandrel may be made of considerablelength without undulyincreasing.

the size of the rolls. After the completion of a working or reducingstroke the billet is released from the grip of the rolls, and Vthemandrel and billet are returned to initial position and during thismovement the `billet is advanced on the mandrel by means of the cylinderand piston 37. As is Well ilmcwn in the art the axial rolling of thebillet has a tendency to open up the metal adjacent to and along itsaxis thereby facilitating the penetration of the mandrel into the billetat each feed movement.

While for convenience of illustration and description it has been setforth with some nal and external dimensions of the billet and then as a.part of the same operation reducing the external dimensions of the S8me.

2. The method of manufacturing seamlessv tubes-which consists inalternately and successively increasing the internal and externaldimensionsof a billet and reducing the external dimensions thereof.

3. The method of manufacturinff seamless.

tubes which consists in progressively increasing the internal andexternal dimensions of a billet and progressively as a part of the sameoperation reducing its external dimensions.

4. The method of manufacturing seamless tubes which consists inenlarging the external dimensions of a billet by a radially acting forceand then as a part of the same operation reducing the externaldimensions.

' The method of manufacturing seamless 5 tubes which consists inprogressively step by stepy increasing the internal dimensions of ahollow billet and then step by step reducing the thickness of the wallof the billet while maintaining the increased internal di- 1.0 mensions.

' my hand.

' OTTO BRIEDE.

Witnesses:

'HENRY HASPER,

WoLneMAn HAUPT. Y

